The present invention relates to oral compositions, such as dentifrices, toothpastes and mouthwashes, which provide an anticalculus benefit. The present invention further relates to methods for inhibiting or reducing calculus.
Dental calculus, or tartar as it is sometimes called, is a deposit which forms on the surfaces of the teeth at the gingival margin. Supragingival calculus appears principally in the areas near the orifices of the salivary ducts; e.g., on the lingual surfaces of the lower anterior teeth and on the buccal surfaces of the upper first and second molars, and on the distal surfaces of the posterior molars.
Mature calculus consists of an inorganic portion which is largely calcium phosphate arranged in a hydroxyapatite crystal lattice structure similar to bone, enamel and dentine. An organic portion is also present and consists of desquamated epithelial cells, leukocytes, salivary sediment, food debris and various types of microorganisms.
As the mature calculus develops, it becomes visibly white or yellowish in color unless stained or discolored by some extraneous agent. In addition to being unsightly and undesirable from an aesthetic standpoint, the mature calculus deposits are regarded by many as a constant source of mechanical irritation of the gingiva.
A wide variety of chemical and biological agents have been suggested in the art to retard calculus formation or to remove calculus after it is formed. Mechanical removal of this material periodically by the dentist is, of course, routine dental office procedure.
The chemical approach to calculus inhibition generally involves chelation of calcium ion and/or crystal growth inhibition which prevents the calculus from forming and/or breaks down mature calculus by removing calcium.
The literature discloses a number of chelating agents for this purpose. British Patent 490,384, Feb. 15, 1937, discloses oral compositions containing ethylenediaminetetraacetic acid, nitrilotriacetic acid and related compounds as anticalculus agents. U.S. Pat. No. 3,737,533, June 5, 1973 to Francis discloses oral compositions containing certain carbonyl diphosphonates. U.S. Pat. No. 3,678,154, July 18, 1972 to Widder et al. discloses oral compositions containing certain polyphosphonates and fluoride.
Organic polymeric agents have also been taught for use as anticalculus agents. For example, U.S. Pat. No. 3,429,963, Feb. 25, 1969 to Shedlovsky discloses copolymers of maleic anhydride and ethylene, and polyacrylic acid having an average molecular weight of 1500 and greater. Another example is Dyroff et al; U.S. Pat. No. 4,289,753; Issued Sept. 15, 1981 which discloses that oral compositions containing certain bis(carboxyalkoxy)butanedioic acid compounds inhibit dental calculus formation. Also, U.S. Pat. No. 4,138,477, Feb. 6, 1979 to Gaffar discloses compositions effective in preventing calculus containing as the essential agent a zinc-polymer combination, with the anionic polymer containing carboxylic, sulfonic and/or phosphonic acid groups. In spite of the many known types of anticalculus agents, the need for improved anticalculus products still exists.
Accordingly, it is an object of the present invention to provide oral compositions comprising certain types of polycarboxylic acids, or their pharmaceutically-acceptable salts, and a pharmaceutical carrier, which compositions can deliver an effective anticalculus benefit. It is a further object of the present invention to provide such an anticalculus product in the form of compositions which do not inhibit remineralization of the teeth, and which are cosmetically acceptable. It is a further object of the present invention to provide an effective method for treating calculus utilizing the polycarboxylic acid-based compositions of the present invention.